1. Field of the Invention
The present invention relates to a lever type connector capable of fitting or detaching one connector housing into or out of another connector housing, using a small force by a rotating operation of a lever.
2. Description of the Related Art
In connectors like a multi-pin connector requiring large fitting or attachment force, a lever type connector provided with a lever is conventionally used so that the lever assists the attachment force. The lever type connector comprises a first connector housing (e.g. male connector housing); a lever rotatably provided in the first connector housing, the lever having a cam groove thereon; and a second connector (e.g. female connector housing) provided with a projection portion being fitted to the cam groove. In a first step of fitting the first and second connector housing to each other, the lever is positioned to face the projection portion at an entrance of the cam groove. In the next step, the lever is rotated to guide the projection portion into the cam groove, and finally both the first and second connector housings are completely connected to each other. In this case, leverage by the lever is utilized to reduce the force required for connecting the connector housings.
FIG. 1 and 2 are schematic diagrams showing a conventional lever type connector disclosed in Japanese Patent Laid-Open Publication 2002-025696. FIG. 1 is a plan view explaining a state of the conventional connector in which a projection portion slightly enters into a cam groove of a lever. FIG. 2 is a plan view of a final state of the conventional connector when the lever is completely rotated to fit a first connector housing to a second connector housing.
As shown in these figures, this type of lever connector comprises a pair of a first connector housing 110 and a second connector housing 150 being fitted to the first connector housing 110. The housings accommodate terminals (not shown) in terminal cavities provided therein. The first connector housing 110 has a lever 130 formed with a square U-shaped cross section. The lever 130 has a hole 132 in a base portion thereof a cam groove 140 thereon and a handle 149 in an end thereof.
The cam groove 140 is provided around the hole 132 within a predetermined angle range with respect to the hole 132. The cam groove 140 is formed from a curvilinear groove entrance 141 so that an end of the cam groove 140 approaches closer to the hole 132. A supporting shaft 111 is provided on an outer wall of the first connector housing 110, and the shaft 111 is rotatably engaged with the hole 132 of the lever 130, whereby the lever 130 can rotate around the supporting shaft 111 within the predetermined angle range.
On the other hand, the second connector housing 150 has a pin 155 projecting from an outer wall thereof, and the pin 155 is provided so as to slidably engage in the cam groove 140. In a state when the first and second connector housings 110, 150 are provisionally fitted to each other, the pin 155 faces to the groove entrance 141 of the cam groove of the lever 130. FIG. 1 shows a state when the pin 155 has slightly entered into the groove 140 from the groove entrance 141.
Two guiding walls 112, 113 are provided on the outer wall of the first connector housing 110. The guiding walls slidably contact the circumference of the base portion of the lever 130 and have eaves 114, 115 on a side facing toward the supporting shaft 111. The base portion is circularly formed around the hole 132. Four grooves 124A, 125A, 124B, 125B are further formed on the circumference of the base portion. Two of the four grooves 124A, 125A engage with the eaves 114, 115 to maintain an initial position of the lever 130 to enable the second connector housing 150 to fit or attach to the first connector housing 110. The other two grooves 124B, 125B engage with the eaves 114, 115 to maintain a final position of the lever 130 in which the fitting is completed. As described above, the second connector housing 150 can be fitted to or detached from the first connector housing 110 by positioning the grooves 124A and 125A; 124B and 125B respectively to the eaves 114, 115 by rotation of the lever 130.
When the first connector housing 110 and the second connector housing 150 are provisionally fitted to each other by positioning the lever 130 in the initial position, the pin 155 faces to the groove entrance 141 of the groove 140. Next, when the lever 130 is rotated toward the final position, the pin 155 enters into the cam groove 140 both by leverage of the lever 130 and by cam action of the cam groove 140. Finally, the first connector housing 110 and the second connector housing 150 are completely fitted to each other when the lever reaches the final position.
During this rotating operation of the lever 130, the circumference of the base portion of the lever 130 is guided by the guiding walls 112, 113 and is slidably supported by the eaves 114, 115. Accordingly, wobble of the lever 130 can be avoided. When the lever 130 is completely rotated to the final position as shown in FIG. 2, the first connector housing 110, the second connector housing 150 and the terminals thereof are correctly connected to each other.
When detaching the second connector housing 150 from the first connector housing 110, the lever 130 is backwardly rotated to the initial position. The leverage of the lever 30 and the cam action of the cam groove 140 pushes out the second connector housing from the first connector housing by guiding the pin 155 in the cam groove to the groove entrance 141. The housings are finally detached from each other when the lever 30 is completely rotated to the initial position.
In the above lever type connector, the rotating operation of the lever 130 creates the fitting or fitting force, however, the lever 130 is subjected to stress during the operation. If this stress is considerably large, the lever could unexpectedly deform or warp. Further, in the worst case, the lever could detach from the supporting shaft 111. The eaves 114, 115 and the guiding walls 112, 113 are provided to avoid these problems. However, The eaves and guiding walls have always to contact with the circumference of the base portion of the lever 130, thus rotation resistance of the lever 130 is so large that the rotating operation of the lever 130 could be difficult. The grooves 124A, 125A and the eaves 114, 115 restrict direction of the lever 130 when the lever is installed, however, the lever 130 is prone to be instead incorrectly.